Types of structural chromosome aberrations and their incidences in human spermatozoa X-irradiated in vitro.
We studied the effects of in vitro X-irradiation on human sperm chromosomes, using our interspecific in vitro fertilization system between human spermatozoa and zona-free hamster oocytes. 28 semen samples from 5 healthy men were exposed to 0.23, 0.45, 0.91 and 1.82 Gy of X-rays. Totals of 2098 and 2862 spermatozoa were karyotyped in the control and the irradiated groups, respectively. The incidence of spermatozoa with X-ray-induced structural chromosome aberrations (Y) increased linearly with increasing dosage (D), being best expressed by the equation, Y = 0.08 + 34.52 D. The incidence of breakage-type aberrations was more than 9 times higher than that of exchange-type aberrations. Both of them showed linear dose-dependent increases, which were expressed by the regression lines, Y = -0.014 + 0.478 D and Y = -0.010 + 0.057 D, respectively. The incidence of chromosome-type aberrations was about 6 times higher than that of chromatid-type aberrations. Their dose-dependent increases were expressed by the regression lines, Y = -0.015 + 0.462 D and Y = -0.006 + 0.079 D, respectively. These results are discussed in relation to the previous data obtained with gamma-rays. The repair mechanism of X-ray-induced sperm DNA lesions is also discussed.
Kamiguchi
Y
Y
Department of Biological Sciences, Asahikawa Medical College, Japan.
Tateno
H
H
Mikamo
K
K
D000818:Animals; D002875:Chromosomes / Q000528:radiation effects* / Q000648:ultrastructure; D004247:DNA / Q000528:radiation effects; D004260:DNA Repair; D004307:Dose-Response Relationship, Radiation; D005306:Fertilization; D006801:Humans; D066298:In Vitro Techniques; D015994:Incidence; D007621:Karyotyping; D008297:Male; D009865:Oocytes / Q000502:physiology; D013094:Spermatozoa / Q000528:radiation effects* / Q000648:ultrastructure; D014965:X-Rays
D004247:DNA